The features of the light emitting diode (LED) mainly include the small size, high efficiency, long life, quick reaction, high reliability, and fine color. So far, the LED has been applied to electronic devices, vehicles, signboards, traffic signs, and many other applications. Along with the launch of the full-color LED, LED has gradually replaced traditional lighting apparatus such as fluorescent lights and incandescent lamps.
Referring to FIG. 1, a light-emitting device 1 includes a p-type electrode and an n-type electrode. The p-type electrode includes p-type bonding pads 14, two first armed electrodes 14a extending from the p-type bonding pad 14, and second armed electrodes 14b interposed between two first armed electrodes 14a. The current is injected from the p-type bonding pad 14 and spread by the armed electrodes. The n-type electrode includes n-type bonding pads 15, third armed electrodes 15a, and fourth armed electrodes 15b. The current is injected from the p-type electrode, moves to the light-emitting region of the light-emitting device 1, and then flows to and out of the n-type electrode. The p-type armed electrodes 14a, 14b and the n-type armed electrodes 15a, 15b are interdigitated between each other.